氢氟酸刻蚀对Ni/6H-SiC接触性质的作用

采用浓度为10%的氢氟酸（HF）刻蚀6H-SiC单晶片，研究了HF刻蚀时间对Ni/6H-SiC接触性质的影响．经24?h刻蚀的SiC基片在溅射Ni层后，其接触表现良好线性的电流-电压（I-V）曲线．低于这个腐蚀时间的接触具有明显的势垒，但在大于1000℃快速退火后，也得到了良好线性的I-V曲线．X射线衍射（XRD）和俄歇能谱（AES）深度元素分析表明Ni₂Si和C是快速退火后的主要产物．XRD和低能反射电子能量损失谱表明表层的C 关键词： 欧姆接触 SiC 富碳层 互扩散

Effect of hydrofluoric acid etching time on Ni/6H-SiC contacts

The effect of hydrofluoric acid （HF） etching time on Ni/6H-SiC ohmic contacts was investigated． The as-deposited Ni/6H-SiC contacts prepared by 6H-SiC substrates which have been subjected to different HF etching time have different I-V characteristics． For SiC substrates etched for less than 12 hours, the contacts were rectifying, and excellent linear curves were observed after high temperature thermal annealing．X_ray diffraction, Auger electronic spectroscopy and low_energy reflection electron energy loss spectroscopy showed that Ni₂Si and amorphous C were the main reaction products after annealing.For SiC substrate etched for 24 hours, the as-deposited Ni/6H-SiC contact was ohmic． The carbon-enriched layer （CEL） on the SiC surface plays an important role in the formation of ohmic contact．